EP2640784B1 - Thermoplastic molding compounds based on styrene copolymers and polyamides, method for producing same and use thereof - Google Patents

Description

The present invention relates to thermoplastic molding compositions containing styrene copolymer, polyamide, graft rubber, compatibilizers and flow improvers based on acrylates, processes for their preparation, thermoplastic molding compositions obtainable by these processes, the use of these thermoplastic molding compositions and moldings, fibers and films containing them contain thermoplastic molding compositions.

Polymer blends of (methyl) styrene-acrylonitrile copolymers and polyamides are known per se. Binary blends of these polymer components have very poor toughness due to the incompatibility between polyamide and, for example, styrene-acrylonitrile copolymer. By using compatibilizers, the toughness of the blends, but also their chemical resistance, can be significantly improved, as described, for example, in US Pat EP-A 202 214 . EP-A-402 528 and EP-A 784 080 , The mixing order of the polymer components and compatibilizer in the preparation of the blends of (methyl) styrene-acrylonitrile copolymers and polyamides is described in the cited documents as basically arbitrary, usually all components are fed together to a mixing device, ie in a single process step at the same time melt distribution mix. Suitable compatibilizers are, in particular, styrene-acrylonitrile-maleic anhydride terpolymers, styrene-N-phenylmaleimide-maleic anhydride terpolymers and methyl methacrylate-maleic anhydride copolymers. It is assumed that the amino or carboxyl end groups of the polyamides react with the functional groups of said copolymers and terpolymers, forming in situ copolymers which produce the compatibility between the styrene copolymer phase and the polyamide phase.

In WO 2008/101888 are described molding compositions based on polyamides, styrene polymers and terpolymers, but is not referred to the flow improvers. In EP-A 2251377 are presented molding compositions of SAN copolymers, glass fibers and a flow improver, but no polyamide-ABS compositions are described with compatibilizers.

Efforts to reduce the weight of plastic components (especially in vehicle construction) that have no structural function are described e.g. possible by lowering the wall thickness. However, as known to those skilled in the art, a reduction in wall thickness in injection molding results in an increase in fill pressure and a decrease in the flow path

It was therefore an object of the present invention to improve the flowability of thermoplastic molding compositions.

1. a) 3 bis 91,8 Gew.-% eines oder mehrerer Styrolcopolymere als Komponente A,
2. b) 3 bis 91 Gew.-% eines oder mehrerer Polyamide als Komponente B,
3. c) 5 bis 50 Gew.-% eines oder mehrerer Pfropfkautschuke als Komponente C,
4. d) 0,1 bis 25 Gew.-% eines oder mehrerer Verträglichkeitsvermittler als Komponente D und
5. e) 0,1 bis 5 Gew.-% eines Fließverbesserers auf Basis von Acrylaten als Komponente E,

Accordingly, new and improved thermoplastic molding compositions have been found which contain:

1. a) from 3 to 91.8% by weight of one or more styrene copolymers as component A,
2. b) from 3 to 91% by weight of one or more polyamides as component B,
3. c) 5 to 50% by weight of one or more graft rubbers as component C,
4. d) 0.1 to 25 wt .-% of one or more compatibilizer as component D and
5. e) 0.1 to 5% by weight of a flow improver based on acrylates as component E,

wherein the wt .-% in each case based on the total weight of the components A to E and together give 100 wt .-%. The invention also relates to processes for their preparation, thermoplastic molding compositions which are obtainable by these processes, the use of these thermoplastic molding compositions and moldings, fibers and films containing these thermoplastic molding compositions.

• a) 3 bis 91,8 Gew.-% eines oder mehrerer Styrolcopolymere als Komponente A,
• b) 3 bis 91 Gew.-% eines oder mehrerer Polyamide als Komponente B,
• c) 5 bis 50 Gew.-% eines oder mehrerer Pfropfkautschuke als Komponente C,
• d) 0,1 bis 25 Gew.-% eines oder mehrerer Verträglichkeitsvermittler als Komponente D,
• e) 0,1 bis 5 Gew.-% eines Fließverbesserers auf Basis von Acrylaten als Komponente E,
• f) 0 bis 3 Gew.-% niedermolekulare Anhydride als Komponente F,
• g) 0 bis 40 Gew.-% weiterer Kautschuke als Komponente G,
• h) 0 bis 50 Gew.-% faser- oder teilchenförmigen Füllstoffs oder deren Mischungen als Komponente H,
• j) 0 bis 40 Gew.-% weiterer Zusätze als Komponente J,

wobei die Gew.-% jeweils auf das Gesamtgewicht der Komponenten A bis J bezogen sind und zusammen 100 Gew.-% ergeben.In a particularly preferred embodiment, the thermoplastic molding compositions comprise:

• a) from 3 to 91.8% by weight of one or more styrene copolymers as component A,
• b) from 3 to 91% by weight of one or more polyamides as component B,
• c) 5 to 50% by weight of one or more graft rubbers as component C,
• d) 0.1 to 25% by weight of one or more compatibilizers as component D,
• e) 0.1 to 5% by weight of a flow improver based on acrylates as component E,
• f) 0 to 3 wt .-% low molecular weight anhydrides as component F,
• g) 0 to 40% by weight of further rubbers as component G,
• h) 0 to 50% by weight of fibrous or particulate filler or mixtures thereof as component H,
• j) 0 to 40% by weight of further additives as component J,

wherein the wt .-% in each case based on the total weight of the components A to J and together give 100 wt .-%.

1. a) 12 bis 50 Gew.-% eines oder mehrerer Styrolcopolymere als Komponente A,
2. b) 30 bis 60 Gew.-% eines oder mehrerer Polyamide als Komponente B,
3. c) 10 bis 40 Gew.-% eines oder mehrerer Pfropfkautschuke als Komponente C,
4. d) 0,1 bis 25 Gew.-% eines oder mehrerer Verträglichkeitsvermittler als Komponente D und
5. e) 0,2 bis 4 Gew.-% eines Fließverbesserers auf Basis von Acrylaten als Komponente E,

wobei die Gew.-% jeweils auf das Gesamtgewicht der Komponenten A bis E bezogen sind und zusammen 100 Gew.-% ergeben. Oftmals sind auch z. B. 0,02 bis 2 Gew.-% mindestens eines niedermolekularen Anhydrids (z.B. Phthalsäureanhydrid) als Komponente F in den Formmassen enthalten.The thermoplastic molding compositions in another embodiment include:

1. a) 12 to 50% by weight of one or more styrene copolymers as component A,
2. b) 30 to 60% by weight of one or more polyamides as component B,
3. c) 10 to 40% by weight of one or more graft rubbers as component C,
4. d) 0.1 to 25 wt .-% of one or more compatibilizer as component D and
5. e) 0.2 to 4% by weight of a flow improver based on acrylates as component E,

wherein the wt .-% in each case based on the total weight of the components A to E and together give 100 wt .-%. Often z. B. 0.02 to 2 wt .-% of at least one low molecular weight anhydride (eg phthalic anhydride) as component F in the molding compositions.

1. a) 12 bis 50 Gew.-% eines oder mehrerer Styrolcopolymere als Komponente A,
2. b) 30 bis 60 Gew.-% eines oder mehrerer Polyamide als Komponente B,
3. c) 10 bis 40 Gew.-% eines oder mehrerer Pfropfkautschuke als Komponente C,
4. d) 0,1 bis 25 Gew.-% eines oder mehrerer Verträglichkeitsvermittler als Komponente D
5. e) 0,2 bis 4 Gew.-% eines Fließverbesserers auf Basis von Acrylaten als Komponente E,
6. f) 0,02 bis 2 Gew.-% mindestens eines niedermolekularen Anhydrids als Komponente F,

wobei die Gew.-% jeweils auf das Gesamtgewicht der Komponenten A bis F bezogen sind und zusammen 100 Gew.-% ergeben.The invention also provides thermoplastic molding compositions comprising:

1. a) 12 to 50% by weight of one or more styrene copolymers as component A,
2. b) 30 to 60% by weight of one or more polyamides as component B,
3. c) 10 to 40% by weight of one or more graft rubbers as component C,
4. d) 0.1 to 25% by weight of one or more compatibilizers as component D.
5. e) 0.2 to 4% by weight of a flow improver based on acrylates as component E,
6. f) 0.02 to 2 wt .-% of at least one low molecular weight anhydride as component F,

wherein the wt .-% are each based on the total weight of components A to F and together give 100 wt .-%.

1. a) als Styrolcopolymer (Komponente A) ein Styrol-Acrylnitril-Copolymer,
2. b) als Polyamid (Komponente B) ein Polyamid 6,
3. c) als Pfropfkautschuk (Komponente C) ein Pfropfcopolymer mit Polybutadien-Kern und Styrol-Acrylnitril-Pfropfhülle,
4. d) als Verträglichkeitsvermittler (Komponente D) ein Styrol-Acrylnitril-Maleinsäureanhydrid-Terpolymer,
5. e) als Fließverbesserer auf Basis von Acrylaten (Komponente E) ein Poly-n-Butylacrylat-Oligomer, sowie ggf.
6. f) als niedermolekulares Anhydrid (Komponente F) Phthalsäureanhydrid.

The invention also relates to thermoplastic molding compositions containing (or consisting of):

1. a) as styrene copolymer (component A) a styrene-acrylonitrile copolymer,
2. b) as polyamide (component B) a polyamide 6,
3. c) as graft rubber (component C) a graft copolymer with polybutadiene core and styrene-acrylonitrile graft shell,
4. d) as compatibilizer (component D) a styrene-acrylonitrile-maleic anhydride terpolymer,
5. e) as a flow improver based on acrylates (component E) a poly-n-butyl acrylate oligomer, and optionally
6. f) as low molecular weight anhydride (component F) phthalic anhydride.

The invention also relates to processes for their preparation of the thermoplastic molding compositions, the use of these thermoplastic molding compositions and moldings, fibers and films containing or consisting of these thermoplastic molding compositions.

The individual components are explained below:

Component A

As the first component A, the thermoplastic molding compositions according to the invention contain from 3 to 91.8% by weight, in particular from 10 to 60% by weight, preferably from 12 to 50% by weight, of at least one styrene copolymer A, this styrene copolymer A preferably consisting of two or more monomers from the group styrene, acrylonitrile, methyl styrene and methyl methacrylate is constructed. In particular, SAN or other rubber-free styrene copolymers can be used as styrene copolymers be understood. Examples of component A are common copolymer matrices such. B. produced by bulk polymerization, emulsion or solvent polymerization styrene-acrylonitrile copolymers. Also mixtures of matrices are suitable, for example as in Ullmann's Encyclopedia of Industrial Chemistry (VCH-Verlag, 5th edition, 1992, p. 633 f. ).

In a further embodiment of the invention, a molding composition is prepared which contains one or more styrene copolymers A, this styrene copolymer A being composed of two or three monomers from the group consisting of styrene, acrylonitrile and / or α-methylstyrene. The copolymer matrix A is preferably prepared from the components acrylonitrile and styrene and / or α-methylstyrene by bulk polymerization or in the presence of one or more solvents. Preference is given to copolymers A having molecular weights Mw of 15,000 to 300,000 g / mol, wherein the molecular weights z. B. can be determined by light scattering in tetrahydrofuran (GPC with UV detection).

• (A_a) Polystyrolacrylnitril, hergestellt aus, bezogen auf (A_a), 60 bis 85 Gew.-% Styrol und 15 bis 40 Gew.-% Acrylnitril, oder
• (A_b) Poly-α-Methylstyrolacrylnitril, hergestellt aus, bezogen auf (A_b), 60 bis 85 Gew.% α-Methylstyrol und 15 bis 40 Gew.-% Acrylnitril, oder
• (A_c) eine Mischung der Copolymer-Matrix (A_a) und der Copolymer-Matrix (A_b).

The copolymer matrix A can, for. For example:

• (A _a ) polystyrene-acrylonitrile, prepared from, based on (A _a ), 60 to 85 wt .-% of styrene and 15 to 40 wt .-% of acrylonitrile, or
• (A _b ) Poly-α-methylstyrene-acrylonitrile, prepared from, based on (A _b ), 60 to 85 wt.% Of α-methylstyrene and 15 to 40 wt .-% of acrylonitrile, or
• (A _c ) a mixture of the copolymer matrix (A _a ) and the copolymer matrix (A _b ).

The copolymer matrix A can also be obtained by copolymerization of acrylonitrile, styrene and α-methylstyrene.

The number average molecular weight (Mn) of the copolymer matrix A is preferably from 15,000 to 150,000 g / mol (determined by GPC with UV detection).

The viscosity (VZ) of the copolymeric matrix A is (measured according to DIN 53726 at 25 ° C in a 0.5 wt .-% solution in DMF) z. From 50 to 120 ml / g. By bulk polymerization or solution polymerization in, for example, toluene or ethylbenzene, the copolymer matrix A can be prepared by a process as described, for example, in US Pat Plastics Handbook, Vieweg-Daumiller, Volume V, (polystyrene), Carl-Hanser-Verlag, Munich 1969, pages 122f. , Lines 12 ff. Is described.

Component B

The molding composition of the invention further contains 3 to 91 wt .-%, preferably from 30 to 80 wt .-%, in particular from 30 to 60 wt.%, Of one or more polyamides B, which may be homopolyamides, copolyamides or mixtures thereof ,

The polyamides of the molding compositions according to the invention generally have a viscosity number of 70 to 350, preferably 70 to 170 ml / g, determined in a 0.5 wt .-% solution in 96 wt .-% sulfuric acid at 25 ° C according to ISO 307th

Semicrystalline or amorphous resins having a weight average molecular weight of at least 5,000, as described for example in the patents US 2 071 250 . US 2 071 251 . US 2,130,523 . US 2,130,948 . US 2 241 322 . US 2 312 966 . US Pat. No. 2,512,606 and US 3,393,210 are described are preferred.

Examples include polyamides derived from lactams having 7 to 13 ring members, such as polycaprolactam, polycapryllactam and polylaurolactam and polyamides obtained by reacting dicarboxylic acids with diamines.

As dicarboxylic acids alkanedicarboxylic acids having 4 to 12, in particular 6 to 10 carbon atoms and aromatic dicarboxylic acids can be used. Here only adipic acid, azelaic acid, sebacic acid, dodecanedioic acid and terephthalic and / or isophthalic acid may be mentioned as acids.

Suitable diamines are in particular alkanediamines having 4 to 12, in particular 6 to B carbon atoms and m-xylylenediamine, di (4-aminophenyl) methane, di (4-amino-cyclohexyl) methane, 2,2-di (4 -aminophenyl) -propane, 2,2-di- (4-aminocyclohexyl) -propane or 1,5-diamino-2-methylpentane.

Preferred polyamides are Polyhexamethylenadipinsäureamid, Polyhexamethylensebacinsäureamid and polycaprolactam and Copolyamide 6/66, in particular with a proportion of 5 to 95 wt .-% of caprolactam units.

Further suitable polyamides are obtainable from ω-aminoalkyl nitriles such as, for example, aminocapronitrile (PA 6) and adiponitrile with hexamethylenediamine (PA 66) by so-called direct polymerization in the presence of water, for example in US Pat DE-A 10313681 . EP-A 1198491 and EP-A 922065 described.

In addition, polyamides may also be mentioned which are obtainable, for example, by condensation of 1,4-diaminobutane with adipic acid at elevated temperature (polyamide 4,6). Production processes for polyamides of this structure are described, for example, in US Pat EP-A 038,094 . EP-A 038 582 and EP-A 039 524 described.

Furthermore, polyamides which are obtainable by copolymerization of two or more of the abovementioned monomers or mixtures of a plurality of polyamides are suitable, the mixing ratio being arbitrary.

Furthermore, such partially aromatic copolyamides as PA 6 / 6T and PA 66 / 6T have proven to be particularly advantageous, the triamine content is less than 0.5, preferably less than 0.3 wt .-% (see EP-A 299 444 ).

The production of the preferred partially aromatic copolyamides having a low triamine content can be carried out according to the methods described in US Pat EP-A 129 195 and EP-A 129 196 described method.

The following non-exhaustive list contains the mentioned, as well as other polyamides A) in the context of the invention and the monomers contained.

AB-polymers:

PA 4 pyrrolidone PA 6 ε-caprolactam PA 7 Ethanolactam PA 8 capryllactam PA 9 9-amine Opel argon acid PA 11 11-aminoundecanoic PA 12 laurolactam

AA / BB-polymers

PA 46 Tetramethylenediamine, adipic acid PA 66 Hexamethylenediamine, adipic acid PA 69 Hexamethylenediamine, azelaic acid PA 610 Hexamethylenediamine, sebacic acid PA 612 Hexamethylenediamine, decanedicarboxylic acid PA 613 Hexamethylenediamine, undecanedicarboxylic acid PA 1212 1,12-dodecanediamine, decanedicarboxylic acid PA 1313 1,13-diaminotridecane, undecanedicarboxylic acid PA 6T Hexamethylenediamine, terephthalic acid PA 9T Nonyldiamin / terephthalic acid PA MXD6 m-xylylenediamine, adipic acid PA 6I Hexamethylenediamine, isophthalic acid PA 6-3-T Trimethylhexamethylenediamine, terephthalic acid PA 6 / 6T (see PA 6 and PA 6T) PA 6/66 (see PA 6 and PA 66) PA 6/12 (see PA 6 and PA 12) PA 66/6/610 (see PA 66, PA 6 and PA 610) PA 6I / 6T (see PA 6I and PA 6T) PA PACM 12 Diaminodicyclohexylmethane, laurolactam PA 6I / 6T / PACM such as PA 6I / 6T + diaminodicyclohexylmethane PA 12 / MACMI Laurinlactam, dimethyldiaminodicyclohexylmethane, isophthalic acid PA 12 / MACMT Laurinlactam, dimethyl-diaminodicyclohexylmethane, terephthalic acid PA PDA-T Phenylenediamine, terephthalic acid.

As component B, the thermoplastic molding compositions according to the invention may contain one or more polyamides with, based on the entire component B, 0.1-0.2% by weight of triacetonediamine (TAD) end groups.

These may also be mixtures of polyamides with TAD end groups with polyamides without TAD end groups. It is important that, based on component B, 0.1 to 0.2% by weight of triacetonediamine end groups are present overall. Preference is given to 0.14-0.18% by weight of TAD end groups, in particular 0.15-0.17% by weight of TAD end groups.

Component C

The molding composition of the invention further contains 5 to 50 wt .-%, preferably 10 to 40 wt .-% of one or more graft polymers C.

Graft rubbers in the context of the invention are understood to mean core-shell rubbers which may also have a multi-shell structure. Preference is given to graft rubbers which as core have a component with a Tg of less than (-20) ° C, preferably less than (-40) ° C. Suitable rubbers based on diene, acrylate, siloxane and EPDM.

The graft shell preferably consists of styrene and acrylonitrile (z, B, SAN) and / or other copolymerizable monomers. The ratio of hard to soft phase is between 10 to 90 and 70 to 30 parts by weight.

During the polymerization of the hard phase, minor amounts of ungrafted fractions are also formed. These are attributed to the hard phase.

It is also possible to use mixtures of different rubbers. The mixing ratio of the two different rubbers should be 10 to 90 to 90 to 10. It is preferred if the rubbers used differ with respect to their soft phase content by at least 5 wt .-%.

This graft polymer C is preferably composed of a graft base and at least one graft. The graft polymer C is z. B. from two or more monomers from the group butadiene, styrene, acrylonitrile, α-methyl styrene, methyl methacrylate, ethyl acrylate and / or methylacrylamide. For an explanation of the graft polymer C and its preparation, reference is made to the description in FIG Ullmann's Encyclopedia of Industrial Chemistry 5th Edition, VCH, 1992, pp. 633f , directed. The molding composition preferably contains from 10 to 40% by weight of one or more graft polymers C, this graft polymer C being composed of a grafting base of polybutadiene (or, for example, a butadiene-containing copolymer) and at least one grafting layer.

The graft is preferably composed of two or more monomers from the group consisting of styrene, acrylonitrile, α-methylstyrene, ethyl acrylate and / or methylacrylamide. Component C and its preparation will be discussed in more detail later.

• einen Dienkautschuk auf Basis von Dienen, wie z. B. Butadien oder Isopren,
• einen Alkylacrylatkautschuk auf Basis von Alkylestern der Acrylsäure, wie n-Butylacrylat und 2-Ethylhexylacrylat,
• einen EPDM-Kautschuk auf Basis von Ethylen, Propylen und einem Dien,
• einen Siliconkautschuk auf Basis von Polyorganosiloxanen,

oder Mischungen dieser Kautschuke bzw. Kautschukmonomeren enthalten.Suitable rubbers C in the context of the present invention are in particular those which

• a diene based diene rubber such. Butadiene or isoprene,
• an alkyl acrylate rubber based on alkyl esters of acrylic acid, such as n-butyl acrylate and 2-ethylhexyl acrylate,
• an EPDM rubber based on ethylene, propylene and a diene,
• a silicone rubber based on polyorganosiloxanes,

or mixtures of these rubbers or rubber monomers.

Particularly preferred rubber C is a graft polymer comprising a graft base, in particular a crosslinked diene or alkyl acrylate graft base, and one or more graft shells, in particular one or more styrene, acrylonitrile or methyl methacrylate graft shells.

Processes for the preparation of the rubber-elastic polymers are known to the person skilled in the art and described in the literature.

Component D

• C.1 ein vinylaromatisches Monomer,
• C.2 wenigstens ein Monomer ausgewählt aus der Gruppe C₂- bis C₁₂-Alkylmethacrylate, C₂-bis C₁₂-Alkylacrylate, Methacrylnitrile und Acrylnitrile und
• C.3 α, ß-ungesättigte Komponenten enthaltend Dicarbonsäureanhydride enthalten.

As component D molding compositions of the invention contain from 0.1 to 25 wt .-% of compatibilizer, in particular terpolymer based on styrene, acrylonitrile and maleic anhydride and thermoplastic polymers having polar groups. Preferably, polymers are used which

• C.1 is a vinylaromatic monomer,
• C.2 at least one monomer selected from the group C ₂ to C ₁₂ alkyl methacrylates, C _{2 to} C ₁₂ alkyl acrylates, methacrylonitriles and acrylonitriles and
• C.3 α, ß-unsaturated components containing dicarboxylic anhydrides.

As vinylaromatic monomers C.1, styrene is particularly preferred. For component C.2, acrylonitrile is particularly preferred. For α, β-unsaturated components containing dicarboxylic anhydrides and for C 3, maleic anhydride is particularly preferred. Preferably, as Component C.1, C.2 and C.3 used terpolymers of said monomers. Accordingly, terpolymers of styrene, acrylonitrile and maleic anhydride are preferably used. These terpolymers contribute in particular to the improvement of mechanical properties, such as tensile strength and impact resistance.

The amount of maleic anhydride in the terpolymer can vary within wide limits and is generally 0.2 to 4 wt .-% mol%, preferably 0.4 to 3 wt .-%, particularly preferably 0.8 and 2.3 Wt .-% in the component C.1. In this area, particularly good mechanical properties with respect to tensile strength and impact resistance are achieved.

The terpolymer can be prepared in a manner known per se. A suitable method is to dissolve the monomer components of the terpolymer, e.g. Example of styrene, maleic anhydride or acrylonitrile in a suitable solvent, for. For example, methyl ethyl ketone (MEK). To this solution one or optionally several chemical initiators are added. Suitable initiators are, for. B. peroxides. The mixture is then polymerized for several hours at elevated temperature. Subsequently, the solvent and the unreacted monomers are removed in a conventional manner. The ratio between the component C.1 (vinylaromatic monomer) and the component C.2, z. The acrylonitrile monomer in the terpolymer is preferably between 80:20 and 50:50.

In order to improve the miscibility of the terpolymer with the graft copolymer C, it is preferable to select an amount of the vinyl aromatic monomer C.1 which corresponds to the amount of the vinyl monomer in the styrene copolymer A. The amount of component D in the polymer blends of the invention is between 0.1 and 25 wt .-%, preferably between 1 and 20 wt .-%, particularly preferably between 2 and 10 wt .-%. Most preferred are amounts between 3 and 7 wt .-%.

The copolymers generally have molecular weights M _w in the range of from 30,000 to 500,000 g / mol, preferably from 50,000 to 250,000 g / mol, especially from 70,000 to 200,000 g / mol as determined by GPC using tetrahydrofuran (THF) as the eluent and polystyrene -Calibration.

Furthermore, styrene-N-phenylmaleimide-maleic anhydride terpolymers can also be used.

Component E

As component E, the thermoplastic molding compositions of the invention contain from 0.1 to 5 wt .-%, preferably 0.2 to 4 wt .-%, particularly preferably 0.3 to 4 wt .-% flow improver based on acrylates.

Alkyl acrylate oligomers having a weight-average molecular weight in the range of from 1,200 to 4,000 g / mol, preferably 1,500 to 2,000 g / mol, are preferably used. The molecular weight is determined by gel permeation chromatography, preferably using THF as eluent. The calibration is carried out with polystyrene standards. The alkyl acrylates are preferably C _1-12 -alkyl acrylates, in particular C _4-8 -alkyl acrylates.
Butyl acrylates or ethylhexyl acrylates are particularly preferably used, more preferably n-butyl acrylate. The preparation of the alkyl acrylate oligomers is carried out by the known methods of polymerization. The preparation of the polybutyl acrylates is preferably carried out by free-radical polymerization, it being possible to use azo or peroxide compounds as initiators. The preparation of such compounds is z. As described in " Encyclopedia of Polymer Science and Engineering, HF Mark (Ed.) J. Wiley & Sons, New York, 1985, pp. 265 et seq ., Process for the preparation are also described in the same document from page 269ff. The polybutyl acrylates may contain up to 40% by weight, preferably up to 20% by weight, of one or more copolymerizable monomers. Preferred comonomers are selected from the group consisting of acrylates, methacrylates, styrene or its derivatives, maleic anhydride, acrylonitrile and mixtures thereof.

Preference is given to using polybutyl acrylates which are liquid at room temperature.

Component F

As a further component (F), the molding compositions of the invention may comprise at least one dicarboxylic acid anhydride, which is to be understood as a low molecular weight compound which has only one dicarboxylic anhydride group. However, it is also possible to use two or more of these compounds as component F. Dicarboxylic acid anhydrides according to the present invention are monofunctional, that is, they react with the polyamide chains of component B, in particular with the anhydride function of the corresponding compounds. The molecular weight of this compound is generally less than 3000 g / mol, preferably less than 1500 g / mol. These compounds may contain, in addition to the dicarboxylic anhydride group, other functional groups that can react with the end groups of the polyamides but are (much) lower in reactivity than the anhydride function. Suitable compounds F) are, for example, C ₄ -C ₁₀ -alkyldicarboxylic acid anhydrides, for example succinic anhydride, glutaric anhydride, adipic anhydride. Also suitable are cycloaliphatic dicarboxylic acid anhydrides such as 1,2-cyclohexanedicarboxylic anhydride. In addition, however, it is also possible to use dicarboxylic acid anhydrides which are ethylenically unsaturated or aromatic compounds, for example maleic anhydride, phthalic anhydride or trimellitic anhydride. Preference is given to the use of phthalic anhydride.

The proportion of component F is generally from 0 to 3 wt .-% and if component F is contained in the thermoplastic molding compositions of the invention, preferably from 0.02 to 2 wt .-%, based on the total weight of components A to G.

Component G

As component G, the thermoplastic molding compositions contain 0 to 40 wt .-%, preferably 0 to 25 wt .-%, particularly preferably 0 to 15 wt .-% impact modifier rubbers. It is possible to use conventional impact modifiers which are suitable for polyamides.

Rubbers which increase the toughness of polyamides generally have two essential characteristics: they contain an elastomeric portion which has a glass transition temperature of less than -10 ° C, preferably less than -30 ° C, and contain at least one functional one Group that can interact with the polyamide. Suitable functional groups are, for example, carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, carboxylic acid amide, carboximide, amino, hydroxyl, epoxy, urethane and oxazoline groups.

• Olefinkautschuke, z.B. EP-, EPDM-, EB- bzw. EO-Kautschuke, die mit den o.g. funktionellen Gruppen gepfropft wurden. Geeignete Pfropfreagentien sind beispielsweise Maleinsäureanhydrid, Itaconsäure, Acrylsäure, Glycidylacrylat und Glycidylmethacrylat. Weiterhin können funktionalisierte SBS- oder SEBS-Kautschuke verwendet werden, z.B. Kraton®1901 FX.

As rubbers, which increase the viscosity of the blends, z. For example:

• Olefinic rubbers, for example EP, EPDM, EB or EO rubbers, which have been grafted with the abovementioned functional groups. Suitable grafting reagents are, for example, maleic anhydride, itaconic acid, acrylic acid, glycidyl acrylate and glycidyl methacrylate. Furthermore, functionalized SBS or SEBS rubbers can be used, eg Kraton®1901 FX.

These monomers can be grafted onto the polymer in the melt or in solution, if appropriate in the presence of a free-radical initiator such as cumene hydroperoxide.

Furthermore, copolymers of α-olefins may be mentioned. The α-olefins are usually monomers having 2 to 8 carbon atoms, preferably ethylene and propylene. Suitable comonomers are alkyl acrylates or alkyl methacrylates derived from alcohols having 1 to 8 carbon atoms, preferably from ethanol, butanol or ethylhexanol, as well as reactive comonomers such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride or glycidyl (meth) acrylate and also vinyl esters , in particular vinyl acetate, proved to be suitable. Mixtures of different comonomers can also be used. Copolymers of ethylene with ethyl or butyl acrylate and acrylic acid and / or maleic anhydride have proved to be particularly suitable.

The copolymers can be prepared in a high pressure process at a pressure of 400 to 4500 bar or by grafting the comonomers onto the poly-α-olefin. The proportion of the α-olefin in the copolymer is i. a. in the range of 99.95 to 55% by weight.

Such rubbers, which increase the toughness of polyamides, are known per se and, for example in the EP-A 208 187 described.

Another group of suitable impact modifiers are thermoplastic polyester elastomers. Polyester elastomers are understood as meaning segmented copolyetheresters which contain long-chain segments which are generally derived from poly (alkylene) ether glycols and short-chain segments which are derived from low molecular weight diols and dicarboxylic acids. Such products are known per se and in the literature, for. B. in the US Pat. No. 3,651,014 , described. Corresponding products are also commercially available under the names Hytrel® (Du Pont), Arnitel® (Akzo) and Pelprene® (Toyobo Co. Ltd.).

It is also possible to use mixtures of different rubbers.

Component H

As component H, the thermoplastic molding compositions according to the invention may contain this component in an amount of from 0 to 50% by weight, preferably from 1 to 20% by weight, in particular from 10 to 17.5% by weight. Suitable particulate mineral fillers H are amorphous silicic acid, carbonates such as magnesium carbonate (chalk), powdered quartz, mica, various silicates such as clays, muscovite, biotite, suzoite, tin malite. Talc, chlorite, phlogophite, feldspar, calcium silicates such as wollastonite, or kaolin, especially calcined kaolin. According to a particularly preferred embodiment, particulate fillers are used, of which at least 95% by weight, preferably at least 98% by weight of the particles have a diameter (largest dimension), determined on the finished product, of less than 45 μm, preferably less than 40 μm and whose so-called aspect ratio is preferably in the range from 1 to 25, preferably in the range from 2 to 25, determined on the finished product, ie usually an injection molded part.

The particle diameter can be determined, for example, by taking electron micrographs of thin sections of the polymer mixture and using at least 25, preferably at least 50 filler particles for the evaluation. Likewise, the determination of the particle diameter can be carried out by sedimentation analysis, according to Transactions of ASAE, page 491 (1983 ). The weight fraction of the fillers, which is less than 40 microns, can also be measured by sieve analysis. The aspect ratio is the ratio of particle diameter to thickness (largest dimension to smallest dimension). Particularly preferred particulate fillers are talc, kaolin, such as calcined kaolin or wollastonite, or mixtures of two or all of these fillers. Of these, talc having a proportion of at least 95% by weight of particles having a diameter of less than 40 μm and an aspect ratio of from 1.5 to 25, in each case determined on the finished product, is particularly preferred.

As component H fibrous fillers such as carbon fibers, Kallumtitanat whiskers, aramid fibers or preferably glass fibers are used, wherein at least 50 wt .-% of the fibrous fillers (glass fibers) have a length of more than 50 microns. The (glass) fibers used may preferably have a diameter of up to 25 μm, more preferably 5 to 13 microns have. Preferably, at least 70 wt .-% of the glass fibers have a length of more than 60 microns. In the finished molding, the average length of the glass fibers is particularly preferably 0.08 to 0.5 mm.
The length of the glass fibers refers to a finished molded part obtained, for example, after injection molding. The glass fibers can be added to the molding compositions already in the appropriately cut-to-length form or in the form of endless strands (rovings).

Component J

As component J, the thermoplastic molding compositions according to the invention can be used with this component in amounts of from 0 to 40% by weight, preferably 0 to 20% by weight, in particular 0 (in the presence of 0.4) to 10% by weight. Other additives include, for example, processing aids, stabilizers and antioxidants, agents against heat decomposition and decomposition by ultraviolet light, lubricants and mold release agents, flame retardants, dyes and pigments and plasticizers. Their proportion is generally 0 to 40 wt .-%, preferably 0 to 20 wt .-%, in particular 0 (when present 0.2) to 10 wt .-%, based on the total weight of the composition. Pigments and dyes are generally included in amounts of from 0 to 4% by weight, preferably 0 to 3.5% by weight, and more preferably 0 (when present at 0.5) to 3% by weight. The pigments for coloring thermoplastics are well known, see, for example R. Gächter and H. Müller, Taschenbuch der Kunststoffadditive, Carl Hanser Verlag, 1983, pp. 494 to 510 , The first preferred group of pigments are white pigments such as zinc oxide, zinc sulfide, lead white (2 PbCO ₃ .Pb (OH) ₂ ), lithopone, antimony white and titanium dioxide.

Of the two common crystal modifications (rutile and anatase type) of titanium dioxide, in particular the rutile form is used for whitening the molding compositions of the invention. Black color pigments which can be used according to the invention are iron oxide black (Fe304), spinel black (Cu (Cr, Fe) 204), manganese black (mixture of manganese dioxide, silicon oxide and iron oxide), cobalt black and antimony black, and particularly preferably carbon black, which is usually in the form of Furnace or gas black is used (see G. Benzing, Pigments for paints, Expert-Verlag (1988), p. 78ff ). Of course, inorganic color pigments such as chromium oxide green or organic colored pigments such as azo pigments and phthalocyanines can be used according to the invention to adjust certain hues. Such pigments are generally commercially available. Furthermore, it may be advantageous to use said pigments or dyes in a mixture, for example, carbon black with copper phthalocyanines, since the color dispersion in the thermoplastic is generally facilitated.

Oxidation retardants and heat stabilizers which can be added to the thermoplastic compositions according to the invention are, for example, halides of metals of group I of the Periodic Table, for example sodium, lithium halides, optionally in combination with copper (I) halides, eg chlorides, bromides and iodides. The halides, in particular of the copper, may also contain electron-rich n-ligands.
As an example of such copper complexes may be mentioned Cu-halide complexes with, for example, triphenylphosphine. Furthermore, zinc fluoride and zinc chloride can be used. Further, sterically hindered phenols, hydroquinones, substituted members of this group, secondary aromatic amines, optionally in combination with phosphorus-containing acids or their salts, and mixtures of these compounds, preferably in concentrations up to 1 wt .-%, based on the weight of the mixture , usable.

Examples of UV stabilizers are various substituted resorcinols, salicylates, benzotriazoles and benzophenones, which are generally used in amounts of up to 2 wt .-%.

Lubricants and mold release agents, which are usually added in amounts of up to 1% by weight of the thermoplastic composition, are stearic acid, stearyl alcohol, stearic acid alkyl esters and amides, and also esters of pentaerythritol with long-chain fatty acids. Also salts of calcium, zinc or aluminum of stearic acid and dialkyl ketones, e.g. Distearylkelon be used. Furthermore, ethylene oxide-propylene oxide copolymers can also be used as lubricants and mold release agents.

The preparation of the thermoplastic molding compositions according to the invention is carried out according to methods known per se by mixing the components. It may be advantageous to premix individual components. It is also possible to mix the components in solution while removing the solvents. Suitable organic solvents are, for example, chlorobenzene, mixtures of chlorobenzene and methylene chloride or mixtures of chlorobenzene and aromatic hydrocarbons, such as toluene. Preference is given to working without chlorine-containing solvents. The evaporation of the solvent mixtures can be carried out, for example, in evaporation extruders.

The mixing of, for example, dry components A to D and optionally E to J can be carried out by all known methods. Preferably, the mixing is carried out at temperatures of 200 to 320 ° C by coextruding, kneading or rolling the components, wherein the components have optionally been previously isolated from the solution obtained in the polymerization or from the aqueous dispersion. The thermoplastic molding compositions according to the invention can be processed by the known methods of thermoplastic processing, for example by extrusion, injection molding, calendering, blow molding or sintering. The molding compositions of the invention can be used for the production of films, fibers and moldings. In addition, they can be particularly preferably used for the production of body parts in the automotive sector, in particular for the production of large-scale automobile exterior parts.

The invention also relates to corresponding moldings, fibers or films.

The following examples and claims illustrate the invention.

measurement methods

The viscosity numbers VZ of the (methyl) styrene-acrylonitrile copolymers and compatibilizers were determined according to DIN 53726 on 0.5% strength by weight dimethylformamide solution at 25.degree.

The viscosity numbers VZ of the polyamides were determined according to ISO 307 at 0.5% by weight solution in concentrated sulfuric acid (96% by weight H ₂ SO ₄ )) at 25 ° C.
The average particle sizes of the graft copolymers used as rubbers were determined as weight average particle sizes by means of an analytical ultracentrifuge according to the method of W. Scholtan and H. Lange, Kolloid-Z, and Z.-Polymere 250 (1972), pages 782 to 796 , certainly.

The heat resistance Vicat B of the thermoplastic molding compositions was determined by means of the Vicat softening temperature. The Vicat softening temperature was determined according to DIN 53 460, with a force of 49.05 N and a temperature increase of 50 K per hour, on isosticks.

The notched impact strength a _{k of} the thermoplastic molding compositions at room temperature (RT) and - 30 ° C was determined on ISO rods according to ISO 179 1 eA.
The flowability MVI was determined according to ISO 1133 at 240 ° C and 10 kg load. Tensile tests were carried out according to ISO 527 on specimens which were produced at 250 and 270 ° C Masstemperatur.

Production and testing of molding compounds Component A

Styrene-acrylonitrile copolymer with 75% by weight of styrene and 25% by weight of acrylonitrile and a viscosity number of 80 ml / g (determined in 0.5% strength by weight DMF solution at 25 ° C.)

Component B1

The polyamide was 1 B is a polyamide 6, obtained from ε-caprolactam, with a viscosity number of 150 ml / g (measured at 0.5 wt .-% - ig strength in 96% sulfuric acid) is used, for example Ultramid ^® B 27E.

Component B2

As polyamide B 2 was a polyamide 6, obtained from ε-caprolactam, having a viscosity number of 130 ml / g (measured 0.5 wt .-% - in 96% sulfuric acid) and a proportion of triacetonediamine of 0.16 % By weight used.

Component C1

Graft rubber with 62 wt .-% polybutadiene in the core and 38 wt .-% of a graft shell of 75 wt.% Styrene and 25 wt .-% acrylonitrile. Average particle size about 400 nm.

Component C2

Graft rubber with 70% by weight of polybutadiene in the core and 30% by weight of a graft shell of 75% by weight of styrene and 25% by weight of acrylonitrile. Average particle size about 370 nm.

Component D

As component D3, a styrene-acrylonitrile-maleic anhydride terpolymer was used which had a composition of 74.4 / 23.5 / 2.1 (wt%), viscosity number: 66 ml / g

Component E

Poly-n-butyl acrylate oligomer with a molecular weight of 1,700 g / mol (determined at 25 ° C as the weight average by GPC, THF as eluent, polystyrene as standard).

Component F

As component E, phthalic anhydride was used.

Component H

Cut glass fiber with polyurethane size, fiber diameter 14 μm.

Component J

As component H Irganox® PS 802 (di-stearyl-dithiopropionate), Fa. Ciba was used.

Preparation of the molding compositions of the invention

The components were mixed in a twin-screw extruder at a melt temperature of 240 to 260 ° C. The melt was passed through a water bath and granulated. The results of the tests are shown in Table 1. Table 1 V1 V2 3 4 5 V6 7 8th V9 9 10 A 18.8 18.8 18.3 17.8 17.8 13.8 13.3 12.8 18.2 17.7 17.2 B1 41 41 41 41 41 - - - - - - B2 - - - - - 53 53 53 36.6 36.6 36.6 C1 35 28 35 35 28 28 28 23 32 32 32 C2 - 7 - - 7 - - 5 - - - D 4.88 4.88 4.88 4.88 4.88 5 5 5 5 5 5 e - - 0.5 1 0.5 - 0.5 1 - 0.5 1 F 0.12 0.12 0.12 0.12 0.12 - - - - - - H - - - - - - - - 8th 8th 8th J 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Vicat B [° C] 103 103 103 102 103 114 114 114 110 110 110 MVR [ml / 10min] 14.9 17.5 20.0 24.2 23.1 29.2 37.1 44.3 32.1 36.5 43.2 ak, RT [kJ / m ² ] 61.1 67.4 67.1 68.1 72.1 54.3 62.5 64.2 8.3 11.2 11.7 ak, -30 ° C [kJ / m ² ] 14.2 16.9 16.4 16.5 17.9 14.4 16.9 17.0 - - - Reißdehn. [%] Tm 250 ° C 67 87 103 108 125 81 145 151 4.5 4.8 5.4 Tm 270 ° C 32 34 89 95 114 34 141 135 2.9 4.1 4.4

Claims (8)

1. Thermoplastic moulding compositions comprising:

   a) from 3 to 91.8% by weight of one or more styrene copolymers as component A,

   b) from 3 to 91% by weight of one or more polyamides as component B,

   c) from 5 to 50% by weight of one or more graft rubbers as component C,

   d) from 0.1 to 25% by weight of one or more compatibilizers as component D, and

   e) from 0.1 to 5% by weight of a flow improver based on acrylates as component E,

   where each of the % by weight values is based on the total weight of components A to E and these give a total of 100% by weight.
2. Thermoplastic moulding compositions according to Claim 1, comprising:

   a) from 12 to 50% by weight of one or more styrene copolymers as component A,

   b) from 30 to 60% by weight of one or more polyamides as component B,

   c) from 10 to 40% by weight of one or more graft rubbers as component C,

   d) from 0.1 to 25% by weight of one or more compatibilizers as component D,

   e) from 0.2 to 4% by weight of a flow improver based on acrylates as component E,

   where each of the % by weight values is based on the total weight of components A to E and these give a total of 100% by weight.
3. Thermoplastic moulding compositions according to Claim 1 or 2, comprising:

   a) from 12 to 50% by weight of one or more styrene copolymers as component A,

   b) from 30 to 60% by weight of one or more polyamides as component B,

   c) from 10 to 40% by weight of one or more graft rubbers as component C,

   d) from 0.1 to 25% by weight of one or more compatibilizers as component D,

   e) from 0.2 to 4% by weight of a flow improver based on acrylates as component E,

   f) from 0.02 to 2% by weight of at least one low-molecular-weight anhydride as component F,

   where each of the % by weight values is based on the total weight of components A to F and these give a total of 100% by weight.
4. Thermoplastic moulding compositions according to one of Claims 1 to 3, comprising:

   a) as styrene copolymer (component A) a styrene-acrylonitrile copolymer,

   b) as polyamide (component B) a polyamide 6,

   c) as graft rubber (component C) a graft copolymer with polybutadiene core and styrene-acrylonitrile graft shell,

   d) as compatibilizer (component D) a styrene-acrylonitrile-maleic anhydride terpolymer,

   e) as flow improver based on acrylates (component E) a poly-n-butyl acrylate oligomer, and optionally

   f) as low-molecular-weight anhydride (component F) phthalic anhydride.
5. Process for producing thermoplastic moulding compositions according to one of Claims 1 to 4, characterized in that the components are mixed at from 200 to 320°C and extruded, kneaded, or rolled together.
6. Thermoplastic moulding composition that can be produced by a process according to Claim 5.
7. Use of a thermoplastic moulding composition according to one of Claims 1 to 4 or 6 for producing mouldings, foils, or fibres.
8. Mouldings, fibres, or foils comprising a thermoplastic moulding composition according to one of Claims 1 to 4 or 6.